Table 3.

Initial-rate and THB binding and inhibition parameters for WT and mutant SULT1A3

Enzyme	kcat, min−1*	Km 1-HP, nM*	Ki THB, nM*	Kd THB, nM†
WT	120 (17)‡	24 (3.8)	25 (2.7)	23 (2.3)
D86A	97 (18)	27 (3.6)	ND‡	ND‡
E89I	110 (11)	22 (2.1)	ND	ND
Y76A	107 (19)	25 (3.0)	ND	ND

Values in parentheses indicate SD.

^*Initial-rate protocols are described in Materials and Methods.

^†Binding-study protocols are described in Materials and Methods.

^‡Inhibition and binding were not detected.